The present invention is related to a fixing device for disc brake of a bicycle, and more particularly to an adjustable disc brake bracket of a rally bicycle.
A conventional bicycle brake device generally includes two brake shoes mounted on the front and rear forks near the rims of the wheels. The brake shoes are controlled by the handles to clamp or not to clamp the rims so as to brake and decelerate or stop the bicycle.
FIG. 1 shows an improved bicycle brake device. A disc brake apparatus 93 is mounted on the fork 91 near the wheel shaft and can brake a coaxial disc 92 with the wheel shaft. Such disc brake device can more quickly brake the bicycle. The fork 91 is equipped with a fixing structure such as a fixing lug 94 or a fixing hole. A bolt 95 is used to lock the disc brake apparatus 93 on the fork 91.
Furthermore, referring to FIG. 2, the above disc brake device can be applied to rally racing bicycle (so-called BMX) for a racer to more effectively decelerate or stop the bicycle when encountering irregular road face or obstruction.
But not all of bicycles possess the fixing structure for mounting the disc apparatus 93. U.S. Pat. No. 5,957,244 discloses a brake bracket for easily and quickly mounting the disc brake apparatus 93.
The braking force and the pulling force exerted onto the transmission chain of the BMX are greater than a common bicycle. Therefore, the transmission chain is likely to be deformed and elongated. At this time, it is necessary to replace the transmission chain or sprocket and adjust the distance between the front and rear shafts in accordance with the tightness of the transmission chain. A rear claw formed with a split 96xe2x80x2 is mounted on the rear fork for facilitating adjustment of the distance between the front and rear wheels. The split 96xe2x80x2 can be horizontal or inclined.
After adjusting the distance between the front and rear wheels, the disc 92 mounted on the wheel shaft must be also moved back or forth. However, the disc brake apparatus 93 mounted on the fixing lug 94 of the rear end 96 cannot be moved. As a result, the lining plates 93xe2x80x2 can be hardly accurately aligned with the frictional section 92xe2x80x2 of outer circumference of the disc 92. This greatly reduces the braking effect.
The brake bracket, U.S. Pat. No. 5,957,244, which enables the disc brake apparatus to move in accordance with the change of the distance between the front and rear wheels. Such brake bracket is formed with an opening in which the wheel shaft is inserted and locked by a bolt. Once the brake bracket is moved, the bracket can be hardly effectively retained or held. Therefore, such brake bracket can hardly bear the strong frictional torque when braking the bicycle and is likely to swing (angular displacement). This affects the braking effect.
It is therefore a primary object of the present invention to provide an adjustable disc brake bracket which can easily and quickly adjust the position of the disc brake in accordance with the change of the distance between the front and rear wheels of a rally bicycle. Such disc brake bracket is able to bear the strong frictional torque when braking the bicycle and achieve a fully braking effect.
According to the above object, the adjustable disc brake bracket includes an upper bracket, a lower bracket, an adjustment section, an insertion section, a retaining seat and a stop section.